A good A/B test tool should be able to reach the following conclusions:

A beat B or B beat A, so you can stop.

Neither A nor B beat the other, so you can stop.

We can’t conclude #1 or #2 but you’ll need about m more data points to conclude one of them.

The tools I’ve found for analyzing A/B tests can all answer #1. Some of the better ones can answer #3. None of the tools I’ve seen will answer #2 and tell you that A and B are not meaningfully different and that you have enough data to be pretty sure about that. Continue reading ‘When Enough is Enough with your A/B Test’ »

After gradually migrating most of my workflow from Subversion to GitHub I discovered an itty, bitty, tiny, huge freakin’ problem. Part of my old workflow involved me storing code I would use again and again in a public repository then source-ing the code directly into R as needed. It also made this code easy for me to share with others, especially students and collaborators. No problem.

Those in society’s minority who did well in math courses are “shocked” at the suggestion that we change the typical math curriculum. The teaching may be “dismal” but algebra is a “foundation stone” in developing critical thinking skills. “It teaches one how to think.” It’s a little amusing but mostly disheartening to see folks who claim to support more challenging math standards fall back on strawmanarguments, condescension, sarcasm and, my favorite, math errors in their arguments.

Yesterday I got back from a great APSA in Seattle. My undergraduate students were despondent at me having to cancel class Thursday so I could attend. A few were curious about what happens at a scientific conference and asked about the structure. I explained that there would be several thousand political scientists at this conference and that most of the planned interaction would take place in panels. Continue reading ‘Planned Serendipity’ »

I served in the US Navy for a few months in 1986, five years in the early 90s, and another year and a half in the reserves. I was never asked to shoot someone. I never pulled a trigger when the weapon was aimed at a person. I served during, but not “in” the first Gulf War. I served during “peacetime”, or at least that’s how I thought about it. However, over the last few months I have been thinking more about my time in uniform, realizing the lasting and deep effects that experience had on me. Continue reading ‘We all carry the scars’ »